Discovering I may have the cleanest AC power in USA


PS Audio Noise Harvesters are on sale. $50 each.. So naturally I had to buy a pair. 36 hours later in my home.Well I clean the prongs, Caig Gold them, and plug them in.
Nothing.
Nothing.
I am wondering broken? DOA?
I move them to other outlets not on my stereo in the kitchen, in the bathroom (the bathroom has a air cleaner plugged in the same outlet, motor running). OK a single blink.
I remember the dimmer thing. Plug the Noise Harvesters into the stereo again.. and turn on the only dimmer in the place (in the bedroom, on a different circuit) KABLAM!!! Now they are blinking pretty regular. OK they are NOT broken.They also blink when I put them on an Adcom AC box also on different circuit than stereo. Both the Cable internet box and the WiFi box are on it. And yes they blink every minute or so.I checked the Furman REF 20 outlets, no blink. The direct to the amp.. no blink.+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
So I apparently have just naturally the cleanest AC line in America? (For my stereo equipment.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Part of it may be the fact I packed the duplex enclosure 20 amp single line I use for the stereo with small quartz crystals coated with Automotive dielectric grease, in small baggies, the duplex is also the Furutech GTX NCF type, and the wall plugs are also filled with the loose small quartz crystals, plus some flattened baggies of the crystals wrapped around the outside shell of the plugs at the wall
Good thing I only ordered two of the Noise Harvesters. More are not needed. (and I actually do not even need the two. but that is OK. I can keep them as a sentinel, to know if I ever get noise on the lines.
So I do not know if my home made anti noise crystals work magic? (along with the Furutech NCF which is basically a refined version of my own crystals) or if I really do have some of the cleanest AC around. (PS I live in a 90 unit apartment building, folks above below, around me. Things like my frig I have several ferrite cores with the AC zipcord wire wrapped in and around them, ditto air cleaners, lamps..
elizabeth
I'm not really surprised but then again, happy for your dilemma. 😄
A few years back I checked my outlets daily for 3 days and on the hour, when I could, and it never varied more than +/-2 volts. Very stable and dependable and I live in a 30 unit apartment in a valley of apartments.

I think a lot of what we read about poor power is not all that common and that there is a certain "fear factor" factored into a lot of products out there that are supposed to make our audio lives happier.

Granted, there are some bad places to live, not of our choosing, that need said products, but thankfully, you're not one of them. You can check that boogey man off your list. 👍

All the best,
Nonoise
nonoise

I think you are confusing power and noise ,
stable voltage is a good thing but there could be ( is ) a lot of noise on the AC  power lines . 
elizabeth is talking about noise not voltage .
She has tried some of the same things I have ,
I'm curious about the use of the crystals , something I might try .


 
Power to the pebble! Hurray!! Or the automotive grease! Whatever!
Elizabeth, it sounds to me you have only scratched the surface of potential tweaks that exist out there. Heck, make some up on your own. That's what I did. Until now.

Now, I am confident that by a series of incredible coincidences that my system and SQ are thriving on a nearly (nearly) infinite number of variables many of which would be considered unfavorable but that somehow interact in a harmonious augmentation of forces (waves, frequencies, photons, electrons) which have created delightful performance. Now I'm afraid to touch a thing. I think one single crystal or brass cymbal anywhere in the room would bring things crashing down.

My primary 'tweak' now is to meticulously preserve the status quo so that this precarious balance is never disturbed!
Another insight, I was able to find the specific culprits near my stereo which are noise polluters. I thought it was the whole Adcom conditioner. Noooo. It was only the Laptop power supply!  I also put a bunch of clip on ferrites on the laptop cord, but it only softened the blinking some.)  All the rest no noise. The laptop power supply is a BIG noisemaker. I moved it to another AC line and the Adcom turned silent. Then the Plasma TV. but ONLY when turned on. When it is in standby, no noise. So it kind of does not matter much. So the PS Audio Noise Harvesters have more than a simple use. They can help locate offending products!
n80... Sadly the barometric pressure will change later today, destroying the perfection...
@elizabeth I wish you hadn't told me that! I must find a way to overcome it! 
Sorry!                                       
I know it is easy to control humidity, temperature,.. but barometric pressure may be hard to control in any normal building!
This device might very well explain the Rudolph the Reindeer Light Up Nose legend. Is Santa an audiophile? Sleigh rides can be very noisy! All those jingling bells and such....


So the big question is when there is noise indicated on the line do you hear a difference with versus without the device? See a difference on your TV?
vair68robert, I understand that noise is different from voltage but a lot of noise comes from competition from neighboring factors which can affect voltage which is a sign that noise is being introduced in the line. Having a steady line voltage eliminates some of the sources of noise. Not all, but it helps narrow it down some. 
 
All the best,
Nonoise
Clearly I do not have enough noise on the AC lines to hear or see a difference. Even with the one dimmer in use in my apartment.. no change. (If the dimmer did make a change, I would have noticed it before now.. MY LP collection is in the bedroom, so using them the lights on and off a lot while listening. (The Noise Harvester is responding a lot to the dimmer even though the dimmer is on another branch. and the Noise Harvester is at least seventy five feet of wire and a few circuit breakers away from it.
Other folks have commented they can her the difference removing the AC line noise.
MY THREAD HERE is mainly saying I have no need for them. Period. Thus the I have the cleanest power in USA comment. But I do have to say using them to find the products which add noise seems very useful.
My laptop charger in particular is spewing HF junk.
One thing I am going to do is stuff that dimmer box back full of treated crystal baggies. and then see if the results matter to the Noise Harvester. I will report back on the results.            
Added ten minutes later: I pulled out the dimmer, stuffed a few baggies of treated crystals around the back, and wrapped one around each leg of wire. Results: lessened the blinking of the Noise Harvester by about a half. Still clear even blinks, but wider spacing between the blinks. from obviously one source. So the crystals did a little, but not a lot to eliminate the HF noise from the dimmer. The dimmer makes no noise if on full, or off. Only creating hash when actually 'dimming' the two 100 watt bulbs. (Yes I still use incandescent in there. They are not on a lot. and last for many years!
Just what kind of noise is the PS harvesting?
This just in!

Excerpt from Stereo Times review.

“The little lights on the Harvesters blink continually, indicating that noise on the power line is being reduced to harmless light. They are quite busy when I turn on any lights in my listening room: this is, according to PS Audio, because the lights are generating contaminating NOISE. Well, one thing’s certain, when I turn off my lights, whether halogen or standard bulb, the frequency of the lights blinking on the Harvesters slows down significantly. When I turn them back on, the Harvesters light up like the 4th of July.

(Note to self: Oh, I get it! 💡That’s why people like to listen in the dark.)

My first impression of the PS Audio Harvesters during Dave Caplan’s visit was confirmed. Overall, I think the Harvesters quieted the system quite noticeably. This has, in my opinion, a sort of domino effect. Things get noticeably quieter thus the music gains a greater sense of spatial acuity and dimensionality and this, of course, makes music sound more lifelike.

To be honest, I couldn’t detect any differences using a single PS Audio Harvester in my system. Two gave a very subtle impression of lowered the noise floor, giving the music a slightly better feel. Three definitely took some hard edges off massed strings, giving them a smoother feel. Four certainly took the sound closer to what I heard with all five installed. It became obvious why PS Audio sells them in 5-packs! Five appears to be the magic number of units for optimal improvement. And at $399.00, I would have to qualify them as a bargain. Because they can be used in parallel using 5,10, 15 or more isn’t crazy nor unheard of and may provide interesting results (though with all those blinking lights your space might closer resemble an airport landing strip).”


Currently, the sale at Music Direct is two or more... $50 each.So at the sale price five would be $250. not $399.
Since I already have no noise.. I cannot see buying several more just to discover I didn’t have any noise after all....
Seriously, on the amplifier line, the light NEVER blinks.(except if the bedroom light dimmer is on.. then just a steady slow blink blink blink/The Plasma in on the Furman, and the noise is cut from the other duplex in the Furman, and outside of it, nothing.
When I moved the Laptop PS, the noise is not making it back to anything.
Even though I do not seem to need them, they were useful to find noise. And pick out offending noisemakers. Worth $100 to know this.                 
to twoleftears: The ’NOISE’ is HF garbage riding on the AC lines.
I am not 55 yet, but I will get on the waiting list for your 55+ place. It seems perfectly suited for pumps, ventilators, and whatever I may need one day. For music, I will take geoffkait’s battery-powered approach.
Fascinating activity.
I have posted this many times but here is a good explanation of AC power quality......https://www.youtube.com/watch?v=ITkuBgFtTjs
I love my new PSAudio DirectStream Power Plant!   
geoffkait and all

I had a similar effect with the Noise Harvesters ,
I tested the sound effect of using 1 thru 5 , the first noticeable affect 
occurred with 2 but the most dramatic effect was when I used 5 .
I've thought about adding more  someday .
We all know fluorescent lights and dimmers are terrible noise producers ,
also so any motor compressor or furnace fan are large contributors .
My Harvesters  are like xmas tree lights when the furnace kicks on or the dinning room light dimmer is being used .
I place electric tape over the light to guide the light sideways .

I use a filter called Green Wave placed in the outlets of the 
refrigerator , deep freezer , washing machine and computer .
I use AudioPrism Quiet Line filters with the TVs in the house .
All plugged in equipment except the stereo are plugged into
Tripp-lite Isobars , surge protections and some noise filtering .

It was an interesting experiment when listening to a song over and over again when placing different filters in different outlets and hearing the effect . 










The effects of dirty AC, and the benefits of cleaning it up, are actually incredibly easy and free for anyone to demonstrate to themselves. I figured this out by simple logic, tried it out, then proved it by double-blind testing. Takes 10 minutes, if that.

First, how I figured it out. RFI is radio frequency interference. Now one of my cool gadgets as a kid was a crystal radio. Run a wire, any old wire, connect to a crystal and with a rheostat (more wire wrapped around a toilet paper roll, a rheostat) you can tune the frequency and hear music. Or whatever. Minus the tuning what you got is noise. Same noise that is on every wire everywhere. Same noise that is on the wire connected to your stereo- including the wires connecting your components. Including even the wires WITHIN your components. 

Which hints at why Synergistic Research Active Shielding works so well. But, different subject.

Okay. So if I am correct, simple test: flip off all the breakers. This electrically disconnects all the wire in all those circuits leaving only the system powered.

When I did this it was hard to believe how much better everything sounded. Not subtle at all. In your face better.

The cool thing is this is almost tailor made for double-blind testing. I had a friend over, asked his wife what is your favorite track? Would it be okay if I played it twice? In between I walked out to the garage and flipped the breakers. When I came back before I could even ask she jumped up and said what did you do it sounded SO MUCH BETTER! Normal woman. Not an audiophile. Hubby hadn't told her- he thought the whole idea was beyond crazy. Not her. She was blown away. Only thing she cared about, you are NOT flipping those breakers back on!

Now someone paying attention may wonder, what really happened? Was it RFI? Or EMF? 

Well, I thought of that. EMF is generated by electronics running on the same circuit. Simple test, flip breakers only on circuits with things running. Then flip circuits on circuits with nothing running. Tried it. Even with nothing running, flipping those circuits off made a big improvement. The more circuits off, the better. Regardless of what is running or not. Tested this one on a different guys wife. Same result.

What this seems to me to demonstrate is that RFI is a bigger (more audible) problem than EMF. RFI of course is everywhere. The closer and more sources the worse, but its radio waves. Its everywhere. And eliminating it, or even reducing it some, makes a huge improvement.

Its easy. Its free. Its a way to test your ears. (If you can't hear what is obvious to ordinary random women.....) And its an easy, free baseline by which to judge the performance of all things claiming to clean up your dirty, dirty AC.


10,000 Hz and up... is the frequency area of cleaning :
Here is a direct quote from Paul McGwan: " we would look at the Harvester like this. A simple product designed to reduce power line noise above 10kHz. On its input there is a capacitor and a choke (inductor or magnetic device) placed across the power line, forming a simple bandpass filter. At the junction of these two elements energy is singled out at a specific frequency range. We then siphon off the noise energy and use it to fill up a capacitor. When the capacitor gets enough of the energy stored, it triggers an SCR which sends that energy to an LED and the light blinks; thus converting the noise energy to light. Bingo, the noise is removed from the line."
Tonight watching TV on the plasma. The Harvester ion the same duplex as the TV was going crazy. Steady blinking about 3/second.TV off. blinking stopped. (No other outlets affected, seems the Furman keeps the duplex separated electrically.)

elizabeth,


Could it be that it has nothing to do with your electricity supply but "simple" distance from some offending product? The devices you bought may have some use for people who cannot keep electrical components at any distance, it seems. Am I reading your posts right or distance had nothing to do with it?


n80,

Drop in barometric pressure will disturb the balance but will, at the same time, deepen the bass. Play some rap today and check weather forecast for tomorrow to tell you what kind of music to play. Brisk cold days are perfect for some alto, as long as you do not have plasma tweeters.

Hello 2 things to Mention look this up Used by the best in Aviation,
electronics,Audio. Stabilant -2. Tons of awards.Even Nasa uses it
it is far better then Craig , it is a super conductor and still non conductive until a current is fed to it, and verystable  conservatively if you clean all contacts with high quality Isopropyl alcohol ,I use 99% on a Amazon, then a thin coat of Stabilant-22
it will enhance and protect a minimum of 12 years if you are not removing them. Well proven made in Canada. I have been using it for years ,tried Craig,Kontac Silver pastes ,Furutech Nono fluid
they all have to be renewed every year or so ,and still not as good.
great o Vacuum Tube pins also temps to 430+ degrees.
also IFI  Audio AC purifiers at $99 each are outstanding even if you 
have a good line conditioner, dedicated mains- well grounded 
and Gold Copper outlets as I do , you put 1 on each outlet  and in yourconditioner  a cumulative improvement . If nothing else check 
them out . The PS Audio is very good for the money.The Ifi Audio 
is  a bit more extensive in noise reduction . Abbington Audio-UK
is themother company which build good products. They have a US headquarters and full $$ money back 30 days satisfaction 
i buy on Amazon freeprimeshipping ,if anything don’t work out 
free returns  can’t beat-0 risk !!
millercarbon
The effects of dirty AC, and the benefits of cleaning it up, are actually incredibly easy and free for anyone to demonstrate to themselves. I  ... proved it by double-blind testing ... simple test: flip off all the breakers. This electrically disconnects all the wire in all those circuits leaving only the system powered ... this is almost tailor made for double-blind testing. I had a friend over, asked his wife what is your favorite track? Would it be okay if I played it twice? In between I walked out to the garage and flipped the breakers. When I came back before I could even ask she jumped up and said what did you do it sounded SO MUCH BETTER!
That is not a double-blind test.
Now someone paying attention may wonder, what really happened? Was it RFI? Or EMF?
It's impossible to say. The test wasn't valid.
Do the Harvesters need to be on the same individual circuit that your system is getting power from, or can they be anywhere in the house (so long as all house circuits go back to the same one box)?
"That is not a double-blind test."
+1 (I am not sure it really mattered in that situation, but double-blind it was not)
glupson. distance? no. The typical measurable radiation from standard unshielded AC lines has nothing to do with the Noise Harvester.
The ’noise’ on the lines as mentioned can come from as far away as the separate dimmer controlled circuit in the bedroom, as mentioned at least 75 feet of wiring away, (and actual physical distance is a direct twenty feet, through a metal outlet box with a brass cover, through 3000 LP albums on the wall and the wall itself.) (and may een comefor a far greater distance. Distance seems to have no matter on the sort of high frequency hash riding the lines. Filters, like in the Furman conditioner, DO.
For the plasma, the AC cord is two meters. The device only blinks if plugged into the AC duplex same as TV.Now the TV DOES radiate freestanding EMI which I can pick up with the Greelee detector in the air. But the Greelee picks up the same radiation (less intense perhaps) from ANY display, on equipment, laptop..The two types may be from the same cause, but the in the air are not what the Noise Harvester is working on.
In general I have no need to be the ’spokesperson for PS Audio, though I want to clear up confusion, I have no interest is selling/shilling this product.
That it seems to do something? yes, did it perform the miraculous cure of some ailment in my stereo? NO. Was I able to track down some AC garbage spewing offenders. YES.
WOULD I BUY THEM AGAIN no. (since they show I have very little spew) But I can see where other folks with more AC garbage in the line would like to keep using them. You do not know until you try I guess.
All circuits affect the audio circuit unless you’ve gone the route of isolating the audio circuit. That’s why the article from Stereo Times pointed out the Harvester didn’t blink too much or at all with the lights off. Ditto refrigerator. Also, two grounds is better than one. For example a second ground per outlet can be run to the water pipe that is connected to Earth ground. But RFI has many ways of getting into the system inckuding via the air and from RF produced by microchips.
Geoff mentions: "" But RFI has many ways of getting into the system inckuding via the air and from RF produced by microchips. ""
I would add that packing DAC and other HF producers, (if they do not get very hot anyway) Packing DAC with antistatic foam reduces the RFI re-entering the DAC chips etc and actually does reduce the noise in the audio signal.
On my current Mrantz I see no need, but my previous DAC an Adcom Da700 (which was just as good as a Bryston highly praised DAC compared in my own system) Took a LOT of money to beat the Adcom WITH the antistatic foam mod.
The black antistatic foam, not the blue. And since thefoam is electrically conductive, Imperative to protect the circuits from it touching them. And grounding the foam to the chassis.
In the Adcom the chassis never got very warm, even with being packed with the foam. IF the unit does get very warm I would not do this mod to it.
If I were rich and bored. I would make a flexible very thin non-conductive tray to fit various brand DAC units perfectly, and fill the tray with the foam and sell them. A vacuum table, borrowed unit to build a sample shape, and some wholesale 36"by 24" 1/8 and /4 inch foams and a ground..

I live in a very rural area in SE TN.  There are no industrial or commercial facilites within dozens of square miles.  My house is the first structure off the power transformer.  The power line from that utility pole is buried all the way to my home's service entrance.  I have two separate dedicated lines in my listening room, one for the digital front end and the other for the power amps.  There are no light dimmers or video equipment in the room.

I purchased an Akiko Corelli passive power conditioner:

https://www.akikoaudio.com/en/products/488-akiko-audio-power-conditioner-corelli-english

Given the highly favorable reviews, I was expecting dramatic results.  I was not hearing this.  I got curious and wanted to know exactly what was going on and so I bought this:

https://www.alphalabinc.com/product/plm/

It is a power lince meter that displays noise on a power line in mV.  It also has a speaker which makes the noise audible.

The Akiko Corelli was not doing anything.  Sometimes the noise level actually increased with the unit plugged in.  I sold it.

It is quite startling how much noise actually rides on a  residential power line.  I am not convinced a cheap wall wart device such as the Noise Harvester discussed here will do much to reduce that doise no matter the wishfull\ thinking involved.
I do not relish being the one to point out that whilst anti-static foam might possibly have some affect on the static electric charge build-up in the equipment chassis, even when the chassis is grounded, it can have no effect on radio frequency interference RFI, which is a totally different animal. RF has no electrical charge. I hate to be the bearer of bad gnus. 🐂 🐂 🐂
Elizabeth, is it possible to show, with pictures, the cristal bags in places ? I think that Bybee also use some cristal in their device too ?
Have a similar experience where plugging one into the wall yields absolutely no blinking light, but plugging one into my power conditioner certainly has an effect. Mind you this is a house made in the 1920's.The unit actually acts up the most when I power on or off my PC (computer that is).
I got two of those harvesters, also.  My HT/2ch is in the living room on a shared 20A circuit.  When I plugged 1 into the shared wall circuit, it blinked a little and then went out,  When I plug the other one into the front outlet of my Furman Elite 20-PFI, it blinks constantly.  It will stop if I turn my power amps off.  The other one  still doesn't blink either way.  I did switch the harvesters to make sure they were both working.  Most of my components are plugged into the back of the Furman that is plugged into the same shared line.  I really can't say I notice a difference in the sound quality either way.

Anyone have an explanation as to what might be going on?
If the Harvester stops blinking when you turn something off. Clearly that particular something is spewing HF junk into the line. I am going on the possible unmentioned ?fact? that the amps are plugged into the Furman? IF the amps are plugged into the wall.. Then yeah it is a mystery.              
If the amps are plugged into the wall, and not the Furman. Try unplugging everything else going into the Furman .. except the amps left on. Does the (still also plugged in and turned on) Furman Harvester still blink?         
Another crazy wild guess is the amps are sucking up whatever is on the line?? and when turned off that HF junk is free to wander.      
(if the amps use a digital switching power supply those do make HF noise)
I had a similar experience one time when I moved. The little doodads made a significant difference in one home but had zero effect in the next. I believe it is very telling that the new place was a much newer building than the last...

I am one of those so-called ’audiophiles’ who believes in the power of ’clean juice’. Fact is I got a steal on a ESP The Essence power strip because the seller had just paid big bucks to have the power company install a distribution transformer in front of his house and no longer benefited form the ESP.
Since I use the front Furman outlet to connect my TT motor when in use, I had moved the harvesters to other shared wall outlets and very rarely.saw them blink.  After seeing your post, I tried moving them back.  My SS class A/B amps are plugged into the back of the Furman along with most of my other A/V equipment.  I recently moved another similar SS amp I use for surrounds and plugged it directly into the wall, same shared circuit.  Now when everything is on, the harvester blinks bright like a constant strobe while the one in the wall doesn't light.  Now when everything is shut down, the Furman front one still blinks a little and the one in the wall is still dark.
My conclusion is that the Furman surge and noise suppressor is adding noise at least to it's front outlet, but not to the wall line.  The next time I have my rack out I will try plugging one of the harvesters into the back of the Furman to see what happens.  My power amp manufacture suggest plugging them all directly into the wall.  I haven't tried that yet, because I would need more outlets.
When I thought it was my conditioner, I found it was another bit of gear doing the damage (causing the blinking) It can be anything! Finding which items was on great thing about using the Noise Harvesters! I was able to find each offending item. Like you, but at first, I thought it was the small Adcom conditioner causing a problem. NO! It was an item connected to it.
SO I would suggest the Furman is not the problem, but something plugged into it. The noise can travel a long way. Though I do find my Furman blocks from the small power to teh main power, but not between the individual small duplex. The Furman also block from outside, or from inside to outside it.PS: I made my own multiple outlets devices when I did not have enough outlets from the wall. From the wall is also from the wall to a pair of additional duplex!!
With two noise harvestors, when there is noise detected in the line by one, does adding the second cause less noise to show than before?   Seems like this would be a reliable way to determine if these gadgets actually remove noise as well as detect it. 
Post removed 
Interesting question.  Can you plug two into the two receptacles of a socket, or using a simple adaptor, plug two into one receptacle?
@twoleftears to answer your question, yes use an adapter and two or more noise harvesters as many due for example with the daisy chained mc 05 from hfc.
For my Plasma TV, yes adding a second Harvester slows the furious rate of the first one. And both blink alternately, pretty evenly, still fast, but not as fast as before.
Very cool. You don’t find tweaks that actually provide measured evidence that they do what they are advertised to do very often.
I think of the Noise Harvesters more as noise "sniifers" than I do noise reducers, though I don't suppose that they hurt (and, like Elizabeth, I have found that multiple NHs on the same circuit reduces the frequency of their blinking). Using them on my two dedicated 20 amp circuits I have been able to find benefits by swapping to better quality dimmers elsewhere in my house and/or identifying which circuits/appliances seem to add noise. I have star grounded most components and also added a second ground rod on my electrical box with good results. Reduced noise = better sound for little $$$.
@kodak805 , First impression: That meter is cool!
After 2 seconds: It would only make me more neurotic. ;^)
The Alpha Lab Power Line Meter (and/or equivalent device) is the only objective method of determining exactly what noise is on the power line.

To eliminate doubt of the efficacy of the Noise Harvester merely monitor the noise level with the Noise Harvester in and out of the system.

If a $2200.00 highly engineered Akiko Audio Corelli passive power conditioner did nothing to reduce noise artifacts on the power line, I seriously doubt a $50.00 Noise Harvester will have any beneficial effect. 

Any experimentation without a calibrated meter is merely guessing, wishful thinking and a waste of time.
The notion that one device, however expensive ( $2200.00 highly engineered Akiko Audio Corelli passive power conditioner) sets the bar for all others is an incorrect assumption.
I have noticed that my Furman does stop the HF in the toroid transformer. So outside noise does not get in, and inside noise does not get out. Nor does the HF noise added to outlets in the High current get to the low, nor the reverse. The same is true for the normal transformer in the P-600 I own.
The added notion that "" Any experimentation without a calibrated meter is merely guessing, wishful thinking and a waste of time ""Is perhaps closer to being partially true. However it certainly is NOT wholly true. The calibrated meter may AFFIRM what one has found without such a meter, but the experiments with the Noise Harvesters certainly do help one to know what is polluting, and when the blinking stops, that at least that part of the grunge has been located and separated from the system. But since the Noise Harvester is not a full range device (It is for 10,000Hz and above) a meter might be useful. Though not a ’requirement’ as kodak805 wishes to claim.
Forget any speculation as to what a Noise Harvester can and cannot do or what a more expensive device might do better.  Again, without a properly calibrated power line meter there is no objective way to know.

A blinking led will not tell you very much, especially given the tolerances in a cheaply made device.  For the price of less than three Noise Harvesters the doubt is easily resolved.  
With the maxim of all audiophiles: "Where you can spend a little, way better to spend a LOT" I suggest skipping the cheap $150 ’distortion’ gizmo, (which only selects a particular harmonic btw) And splurge twice that or three times that and buy a real oscilloscope from Amazon. Then you get the Whole Enchilada .. And you can analyze your power until the cows come home.         
ADDED: and for less money than $150... you can buy a USB oscilloscope for $80 or so.